Cognitive load
Definition
Cognitive load
- “Cognitive load theory describes how the architecture of cognition has specific implications for the design of instruction. The theory has broad applications in the design of instructional materials, providing a general framework and conceptual toolkit for instructional designers to minimize and control the conditions that create unwanted cognitive load in learning materials.” (Wikipedia
- “CLT is concerned with the design of instructional methods that efficiently use people's limited cognitive processing capacity to apply acquired knowledge and skills to new situations (i.e., transfer). CLT is based on a cognitive architecture that consists of a limited working memory with partly independent processing units for visual and auditory information, which interacts with an unlimited long-term memory.” Pass et al. 2003: Abstract.
In recent years there has been an increased focus on the role of education and training, and on the effectiveness and efficiency of various instructional design strategies. Some of the most important breakthroughs in this regard have come from the discipline of Cognitive Science, which deals with the mental processes of learning, memory and problem solving.
Cognitive load theory (e.g. Sweller, 1988; 1994) is an instructional theory generated by this field of research. It describes learning structures in terms of an information processing system involving long term memory, which effectively stores all of our knowledge and skills on a more-or-less permanent basis and working memory, which performs the intellectual tasks associated with consciousness. Information may only be stored in long term memory after first being attended to, and processed by, working memory. Working memory, however, is extremely limited in both capacity and duration. These limitations will, under some conditions, impede learning
The fundamental tenet of cognitive load theory is that the quality of instructional design will be raised if greater consideration is given to the role and limitations, of working memory. Since its conception in the early 1980's, cognitive load theory has been used to develop several instructional strategies which have been demonstrated empirically to be superior to those used conventionally..(Cooper, 1998)
John Sweller's work is based on an information processing model of cognition, and in particular the limitations of working memory. In addition,“key learning activities are schema acquisition and automation of their usage. After enough training, acquired schemata are stored in long-term memory. They allow high cognitive performance with a very limited working memory” (Heeb 2001: 3). Now when learning concerns multiple interacting elements of information, they have to be learnt at the same time.
Sweller differentiates between intrinsic, germane, and extraneous cognitive load.
- Intrinsic load is related to the difficulty of concepts, i.e. integral complexity of an idea or set of concepts (learning contents). For example, in programming, learning to program "Hello" with Php is much easier than doing it with Java.
- Extraneous load (irrelevant) is due to the design of the instructional materials. In inefficient instructional designs it adds unnecessary load. For example, an audio-visual presentation format usually has lower extraneous load than a visual plus text format, because in the former case, working memory has less information to process.
- Germane load (relevant) relates to the degree of effort involved in the processing, construction and automation of schemas. Germane load is sometimes associated with motivation and interest. Intrinsic load is unchangeable, whereas the instructional designer can manipulate extraneous and germane load.
Sweller's principles and guidelines for instructional designers
Cognitive load theory suggests preventing students from using a means-ends strategy and encouraging them to attend to problem states and their associated moves should reduce extraneous cognitive load and so facilitate schema acquisition. In general, instructional techniques should attempt to reduce extraneaous cognitive load associated with constructing a representation because this facilitates learning.
According to Rebetez (2006:12-13) Sweller, based on his cognitive load theory, describes a series of effects and guidelines to create learning materials:
- Goal free effect: novice learners with a specific learning goal (like a precise question to answer) focus on the goal and pay no attention to other information. This is detrimental to learning.
- Worked examples effect: using known and resolved examples diminish cognitive load and improves comprehension.
- Problem completion effect: the worked out example should be followed by a similar but unresolved problem to maximise motivation.
- Modality effect: two messages on similar elements should be provided through different sensory modalities.
- Split-attention effect: occurs when learners have to process and integrate multiple and separated sources of information. For instance, a geometrical sketch is better understood when textual information is spatially integrated rather than separated . This effect is very similar to Mayer spatial and temporal contiguity principles.
- Redundancy effect: when the same information is presented more than once the multiple processing is negative for comprehension since it increases external cognitive load. If novices can benefit from partially redundant information (integrated text and picture for example), expert's performances can be impaired . These six first effects try to minimize extraneous cognitive load (to reduce the number of cognitive processes involved that are unnecessary for learning).
- Element interactivity effect: interactivity with the material increases negative effects such as split-attention and redundancy effects.
- Isolated interacting elements effect: with complex models containing multiple interacting elements it is advisable to begin with presenting every element separately.
- Imagination effect: mentally simulating the functioning and interaction of elements allow experts to obtain better results.
- Expertise reversal effect: with experts, several effects are inversed. In this case, classical design rules are advisable instead of those funded on cognitive load.
- Guidance fading effect: as expertise is obtained, learners should be less guided in their exercises.
Other Strategies to diminish cognitive load
- Computer-supported authoring tool could scaffold and facilitate cognitive processses by alleviating the cognitive load.
- In collaboration the persons can share cognitive load by dividing it up into smaller portions. Each of them will be mainly treated by one of the persons.
- Appropriate selection of processing strategies can diminuis cognitive load.
On the other hand, the difficulty with metacognitive processes is that they enter into competition with lower cognitive process for resources (especially working memory). Metacognition involves an increased cognitive load. Supporting cognitive and metacognitive processes with tools may benefit the metacognitive layer (which often comes after other attention mechanisms).
Tools
- The NASA-TLX measures task load (Hart & Stabeland, 1988)
References
- Cooper, G., 1998, Research into Cognitive Load Theory and Instructional Design at UNSW, University of New South Wales, Australia, HTML (This URL is dead, but you can find a mangled copy in the Google cache. I do hate Web site killers ! 19:10, 29 August 2006 (MEST))
- Hart, S. G. & Staveland, L. E. (1988). Development of NASA-TLX (Task Load Index): Results of empirical and theoretical research. In P. A. Hancock and N. Meshkati (Eds.), Human Mental Workload (pp. 139-183). Elsevier Science Publishers B. V. (North Holland).
- Raufaste, E., Terrier, P., Grabisch M., Lang, J. & Prade, H. (2001). Etude expérimentale de l'applicabilité de modèles d'agrégation flous à l'étude de la charge mentale. In Journées d'études en Psychologie Ergonomique (pp. 171-176), EPIQUE 2001, Nantes, 29-30 octobre 2001. PDF
- Mayer Richard E. & Roxana Moreno (2003). Nine Ways to Reduce Cognitive Load in Multimedia Learning, Educational Psychologist 2003 38:1, 43-52
- Fred Paas, Juhani E. Tuovinen, Huib Tabbers, Pascal W. M. Van Gerven, Cognitive Load Measurement as a Means to Advance Cognitive Load Theory, Educational Psychologist 2003 38:1, 63-71 Abstract/PDF (Access restricted)
- Heeb, Hanspeter (2001), Roboworld Overcoming the Problem of Cognitive Load in Object-Oriented Programming by Microworlds, Mémoire DESS en Sciences et Technologies de l'Apprentisssage et de la Formation, TECFa, Université de Genève. Zip file
- Sweller, J. (2003). Evolution of human cognitive architecture. In B. H. Ross (Ed.), The psychology of learning and motivation (Vol. 43, pp. 215-266). New-York: Academic Press.
- Sweller, J., Chandler, P., Tierney, J., & Cooper, M. (1990). Cognitive load as a factor in the structuring of technical material. Journal of Experimental Psychology: General, 119, 176-192.
- Sweller, J., van Merrienboer, J. J. G., & Paas, F. G. W. C. (1998). Cognitive architecture and instructional design. Educational Psychology Review, 10(3), 251-296.